The invention provides an adjustable frequency oscillator using a comparator timer. Single means, such as a potentiometer, concurrently changes both charging current and threshold trip voltage to change the frequency of oscillation of the comparator output.
The circuitry features expanded frequency range, reduced power consumption and improved adjustment resolution.
Though not limited thereto, the oscillator was developed for proximity switches and is particularly useful in photoelectric type proximity switches for timing a delayed output signal following a given sensed condition. The wide range together with the low power consumption makes the oscillator ideal for such proximity switch application.